I'm pretty sure your talking about Vertebrates
The UV rays cause sun spots due to reaction from the radiation.
Answer:
Empirical: OH
Molecular: 
Explanation:
First of all, we are going to use the formula: mass = no. moles x Molar Mass And rearrange it to find No. moles: No. moles = mass/Molar Mass
Let's start with Hydrogen:
The given mass is 0.44g, and hydrogen's molar mass is 1.01, therefore the number of moles is: 0.44/1.01 = 0.4356
Now we do the same for Oxygen:
Given mass = 6.92, Molar mass of Oxygen = 16.00, No. Moles = 6.92/16.00 = 0.4325
Now we identify the smaller one (Oxygen as 0.4325 < 0.4356) and we divide both values by that number:
0.4325/0.4325 = 1
0.4356/0.4325 = 1.01
We round both to the nearest 0.2 or 0.25 (depending on what you're taught), and we get: 1 and 1.
This means that the empirical formula has one of each: OH
Now to find the molecular formula we find the relative mass of OH and divide the given mass by that:
M(OH) = 16.00+1.01 = 17.01
34.00/17.01 = 2
We now multiply both by this number to get:

Hope this helped!
Answer:
Mutation, fertilization, meiosis are different mechanisms by which changes can occur in the genome.
Explanation:
There are several process which is responsible for causing change in the genome of the species which results in the evolution of that species. Some of these processes are:
1. Mutation: In mutation, some nucleotide sequences get change and this change can occur due to frameshift, addition, deletion or any other process. This change in nucleotide can be seen in phenotype and helps in the evolution of the species.
2. Fertilization: During fertilization mixing of the genome of two individual takes place which results in producing a genetically distinct offspring which contains variation. So as the offspring is genetically different it can contain new alleles that can help the individual to survive in the changing environment.